The purpose of final project is to analyze the influence of personal factor’s on customer’s decision. Impact of using prepaid electricity by customer’s at PT. PLN (Persero) Rayon Semarang Selatan. The majority of customer’s at PT. PLN (Persero) Rayon Semarang Selatan still use postpaid electricity. Whereas PT. PLN (Persero) Rayon Semarang Selatan has informed the advantages of prepaid electricity than postpaid electricity and PT. PLN (Persero) will carry out a policy to require all customer’s to use prepaid electricity, to reduce losses by PT. PLN (Persero). Customer’s decision are influenced by personal factors that arise from within the customer’s. This final project was arranged based on questionnaires distributed to all prepaid electricity customer’s at PT. PLN (Persero) Rayon Semarang Selatan and study literature. The data analysis was simple linear regression. The variable of this final project are personal factor and customer’s decision to use prepaid electricity. The sampling technique that used in this final project was incidental sampling methods. The population of this final project were prepaid electricity customer’s at PT. PLN (Persero) Rayon Semarang Selatan. The samples of this final project were 100 respondents The results showed 63,3% customer’s decision to use prepaid electricity at PT. PLN (Persero) Rayon Semarang Selatan was determined by personal factor. While the rest of 36,7% was affected by other factors. Then in t test, there was a positive significant influence of personal factor on customer’s decision from the value of t for personal factor is 13,094> value of t table 1,987 with the results of significance of 0,000 < 0,005. Therefore, the company is expected to increase personal factors ton customer’s decision to use prepaid electricity